Meter reverse control mechanism



Jan. 24, 1933. H. G. WEYMOUTH 1,895,059

METER REVERSE CONTROL MECHANISM Filed March 15. 1928 F %Mg&IN;ENTOR. By W QM ATTORNEY Patented Jan. 24, 1933 v UNITED STATES PATENT OFFICE HARRY G. wnY vrourn, or PITTSBURGH, PENNSYLVANIA, AssreNoa '10 PITTSBURGH EQUITABLE'METER COMPANY, or PITTSBURGH, PENNSYLVANIA, A CGRPOBATION or PENNSYLVANIA METER REVERSE CONTROL MECHANISM Application filed'March.15,1928. Serial No. 281,798.

sure at, the outlet side ofv the meter whichtends to force the gas back through the meter into the service main and effect a backward rotation of th'e indicating mechanism.

If a reverse or backward movement of the tangent arm of a meter is not provided for, when the gas is shut off at the consuming appliances equalization of pressure at the inlet and outlet sides of the meter would be slow if the valve, were tight and remained seated. Such resulting difference of pressure would effect an undesirablestrain on the meter mechanism possibly sufiicient to break or to permanently deform the mechanism to such an extent as to impair the accuracyand effectiveness of themeter. i i

It has been observed'in practice that in order to substantially equalize said pressure rapidly sufliciently to obviate danger of injury to the mechanism it is sutficient that the meter parts be permitted to move backward or in a reverse direction somewhat less one complete revolution. 7'

Various attempts have heretofore been made to overcome this well recognized tendency of building up unequal pressures in a meter by providing for a reverse rotation of the tangent arm and related'parts, and consequently the indicating mechanism to allow for the equalization of pressures on the inlet and outlet sides of the meter. p

y In. the constructions heretofore proposed the tangent arm was permitted to'move in a reverse direction suflicient for the substantially immediateequalization of said unbalanced pressures but was permitted tofmove in the reverse direction for a variable range of from one to two complete revolutions which was more than necessary to allow for equalization of the pressures and consequently reversed the movement of the indicating mechanism to a greater degree than neces sary. A 7 It is accordingly a primary object of this invention to provide mechanisms permitting the tangent arm and related parts of a gas meter to move in a reverse direction a predetermined distance sufricient to overcome said unbalanced pressures without reversing the indicating mechanism to an extent more than necessary. A

It 'is'another object-of my invention to provide means for positively arresting backward movement of the tangent arm and related parts after substantially onecomplete reverse revolution has been completed thereby.

It is a further object of this invention to provide stop mechanism for positively arresting movement of the tangent arm and connected parts after having made substantially one complete reverse revolution irrespective of the initial position and relation of parts. a

It is a still further object of my invention to provide means of the character above referred to that is simple in construction, reliable in operation, and comparatively inexpensive to manufacture.

lVith these objects in view as well as others that will become apparent from the following disclosure, reference will be had tothe accompanying drawing forming a part thereof, and in which,- a

Figure, 1, is a top plan view of an improved form of mechanism and co-operating parts embodying my invention, the meter casing and tangent arm being shown in dot and dash linesfor the sake of clearness and, 5 Figure 2 is a side elevational view of the construction shown in Figure 1.

Referring to the drawing in which is illustrated valve and registering mechanism actuating means of the character employed in the well known type of diaphragm meters, 10' designatesthe crank plate which forms the top of the valve chamber cover and 11 designates ing.13 is a rotatable crank shaft 14 provided,

with crank 15 between plates 10 and 11 to which the valve actuating rods 16 are rotatably secured, shaft 14' above plate 10-being I provided with the usual registering mechanism operating worm 17. Rigidly secured to the outer end of crank shaft 14 is tangent arm 18 which asshown more particularly in dot 'a'nddash lines in Figure 1 is of the duplex adjustable formjcomprising a looped bod portion 19 provided with a yieldable inwar ly extending tongue 21 such as resilient sheet metal, and preferably'sheet brass which ad? jacent its free end is secured to shaft 14. 'A

7 pair of adjusting screws 22 are adjustably' post25 V I i Carried by platelO adjacent shaft 14 is a. bracket 27 preferably of white metal or threaded into the oppositesides of portion 19 in laterally alined position for engagement with tongue 21 to adjust the position of tongue 21 relative "to the sidesof body portion19. 'Tangent arm- 18 furthercomprises an elon ated shank 23 threaded as at 24 for adjusta le engagement therewith of post. 25 which isheld in adjusted position on shank 23 byjamb nuts 26. By these constructions it will be seen'that provisionis madefor both angularfand' throw adj ustment of the. flag arms the outere'nds ofwhich are journaled on bronze which as shown is provided witha laterally extending section 28. 1 Section 28,

adjacentthe end'thereof is apertured for the.

' 'reception'of astationary bushing 29 which provides a convenient bearing torshaft' 14 intermediate worm 17 and tangent arm 18 "Journaled on'bushing 29 through the hub portion 31 is a ratchet'whcel 32 preferably of tinned brass or bronze provided with a i adapted for engagement by a downwardly projecting pin 34 carried by tangent arm 18. v f

Bracket 27 is bifurcated as at 85 providing a pair of spaced alined' apertured ears 36 and pivoted between ears 36 by-means of a pintle'37 such as a bent wire extending through the aperturesin ears'36 is the initermediateiportion f fl gravity Pawl'i 38 whoseupper'end swings inward by gravity into: the depressions formed by the teeth of ratchet'wheel 82. :IP a'wl' 38 is also preferably constructed of tinned bronze or brass. 1 n the operation of the construction above described 'tangent'armlS in the normal operation of the meter, moves in a direction such that pin34 engages lug 33"to move ratchet wheel 32 in the direction indicated by the arrow in Figure 1 in which movement the long inclined edges of the teeth of ratchet wheel 32 successively ride in engagement with the upper end of pawl 38 imparting a continuous rocking motion thereto and "allowing ratchet wheel 32and tangent arm1 8 to rotate freely. If for any cause such for 1 example, as has been abovereferred to, the

gas pressure on the" outlet of the inte'r' ex 'ceeds the gas pressure" at theji nlet thereof, tangent arm 18 will be driven'in 'thereverse the meter causing pin 34 to move away from contact, with lug 33 and to engage the oppo-v siteface of lug 33 after tangent arm 18 has movedsomewhat less than a complete revolution in the reversedirection. Pin 34 upon direction by gaspassing backward through engaging the opposite "face of lug' 33 will V tend to'ro'tate ratchet wheel 32in the reverse .directiomwhich will beprevented b engagement of pawl-38 with the radial e accordingly further reverse movement of tangent arm 18willbe'impos'sible.

It will accordingly be seenthat withfthe relative-proportion,of parts shown tangent arm 18 will be permitted'toinove" me tege an adjacent tooth "of ratchet wheel-32 and verse@(lirection less than ai'complete revolution by an amount "equatto' the sum 'of the widthrof lug 33 andthe diameterof'pinB l' minus'the distance that might exist between ratchet wheel 32'when tangent arm 18 be: gins its'" reverse movement. will be apparent to those skilled in the art that ratchet wheels having varying numbers and sizes of teeth. and lugs33} and pins 34 of different sizes may be providedand by proportionin i the parts pro any the reverse movement o si n le revolution. v n p rom the foreg oing' disclosure it will'be arm: 18 may ejequal 'to or greater than a seen that an improved reverse'movementcontrol means for gasmeters 1s providedwhlch is simple in construction and whichu'pon the existen'ceof nnb'alancedgas pressures above referred to will permit thef mechan'ismfto move in a reversedirectiona predetermined and substantially uniform amount just sulficient to provide for satisfactory equalization of pressuresobviating danger to the mechanisms, The'construction is furthermore such that the rev'erse movement will be substantially umform in successive reverse operations regardless of the-relative position of parts at the beginning of the reverse move Having disclosed but mingle embodiment my invention is notlimited'thereto but inpawl 38" and radial edge 'ofadjacent tooth of of my invention itistobeunderstood that cludes such "changes or' alterations as [fairly fall within the scop'efof the s'ubjoined claims.

'- Accordingly, what I claim and desire to secure by United States Letters Patent is lfIn a'gas meter the combination of "a driven shaft; a tangent arm carried by said shaft; and stop means for arresting movement of said tangent arm and said shaft after a substantially fixed range of'reverse movement thereof.

2. In combination with the crank shaft and tangent arm of a gas meter, a stop detent vmechanism supported by said meter for cooperation with said tangent arm to arrest movement thereof after slightly less than one complete reverse revolution independently of the point from which said reverse rotation is initiated.

3. In combination with the crank shaft and tangent arm of a gas meter, stop means cooperating with said tangent arm for permitting a uniform range of reverse movement of said tangent arm and shaft irrespective of the relative position of said tangent arm at the beginning of said reverse movement.

i. In a gas meter the combination of a driven shaft, a tangent arm carried by said shaft; a projection carried by said tangent arm; amember carrying a second projection constantly in contact with said first projection and movable therewith upon movement of said tangent arm in one direction; means for preventing movement of said second proj ection in the opposite direction for arresting movement of said tangent arm by engagement of said first projection with said second projection upon substantially one complete reverse revolution of said tangent arm.

5. In combination with the crank shaft and tangent arm of a gas meter; a bracket supported adjacent said crank shaft and providing a bearing therefor; a ratchet wheel rotatably supported by said shaft adjacent said bracket co-operating engaging members carried by said tangent arm and said ratchet wheel; and a pawl pivoted in said bracket for co-operation with said ratchet wheel for limiting rotation thereof to one direction only.

6. Incombination with the crank shaft and tangent arm of a gas meter; a bracket supported adjacent said shaft; a bushing supported by said bracket and providing a bearing for said shaft; a ratchet wheel journaled on said bushing; a lug carriedby said ratchet wheel; a pin carried by said tangent arm for engagement with said lug for imparting movement of said tangent arm to said ratchet wheel; and a gravity actuated pawl pivoted in said bracket for co-operation with said ratchet wheel for preventing reverse rotation thereof.

In testimony whereof I affix my signature.

HARRY Gr. WEYMOUTH. 

